Apparatus for converting starch by a continuous operation into derivatives, dextrin, dextrose, &amp;c.



S. M. LILLIE. APPARATUS FOR GONVERTING STARGH BY A' CONTINUOUS OPERATION INTO DERIVATIVES,

DEXTRIN, DEXTEOSE, &c. APPLIOATION EILED MAY 28, 1910.

Patented Jan. 9, 1912.

UNITED STATES ATENT OFFICE.

SAMUEL MORRIS LILLIE, 'oP PHILADELPHIA, PENNSYLVANIA.

APPARATUS FOR CONVERTING STARGH BY A coNTINUous OPERATION INTO n lnivA- TIVES, nExTRIN, DEXTROSE, 8w.

,- Patented Jan. 9,1912.

To all whom it may concern: 4 Be it known that I, SAMU L Monnrs LILLLE, a citizen of the'United States, residing at Philadelphia, in the county'of Phil'afdelphia and State of Pennsylvania, have m-' vented a new and useful Apparatus for Converting Starch by a Continuous Operation:

into Derivatives, Dextrin, Dextrose, 8110., of which the following is. a specification.

The method usually employed for the conversion of starch into these derivatives is an intermittent operation, which is to nearly fill a closed vessel converter provided with a perforated steam heating coil with. Y

a mixture of starch, water and a small proportion of acid, heat the mixture under; pressure by injected steam to the desired converting temperature, say 280 Fah., shut off the steam and allow the heated mixture to stand until the mass of the mixture has been converted to the desired degree as indicated by a reagent, usually a'solution of iodin. A discharge valve is then opened and the contents of the converter discharged into a tank open to the atmosphere, the vapors due to the reduction in pressure passing away into the atmosphere to waste. The converter is then recharged with the acid istarch mixture and another conversion made. Each batch of converted liquor after leaving the converter is neutralized by a suitable reagent, as carbonate of soda, for example.

' progresses with the duration of itsheated stayin the converter, which if long enough will carry it through the several conditions of starch paste, soluble starch, and dextrin to dextrose. The charge is kept in the converter until it has arrived at the desired degree of conversion- The portion of the charge first to leave the converter is less converted than the portion which leaves the converter last, for the latter is subjected to the heat as much longer than the former as it takes to empty the converter, and the two show with reagents quite different stages of conversion. This lack of uniformity in the conversion is one ofthe faults of this usual method of converting starch which it is the purpose'of my invention to obviate. the loss of heat in the escaping vapors and the intermittent demand for steam on the boilers. The'converter makes a heavy demeans The conversion of the starch serves for draining the same if desired.

Other faults of this process areuntil the next charge is heated,

The purpose of my invention is to provide apparatus adapted to ractice a continuous process of convertmg starch bye 0 heat, acid and water into de-- rivatives, dextrin, dextrose, &c., and to ob tain a practically uniform conversion, a constant draw of steam from the boilers, a use- I ful heating effect fromthe escaping vapors, 5 and other advantages incidental to a continuous process. a

- I show in the accompanying drawings, and describe in the. following specification apparatus illustrative of my invention. The vertical cylinder A is the f converting column vessel. In it are contained a numv ber of horizontal perforated diaphragms n, n, etc., of approximately the same diameter 7 as the interior of the cylinder and equally spaced one above the other, the. lowest diaphragm a little above the bottom of the cylinder, and the uppermost one a little below the top of the cylinder. A discharge pipe D, shown axial in the figure, extends so from bel ow the lowest diaphragm'where it is fitted with the inverted cup u up through them all' and through the top of the cylind r and leads lnto an empty expension chamber T, which has an outlet above through the pipe h, which leadsinto a spray condenser or heater H, hereinafter more fully described. Below, the tank T has a drain pipe 25, which leads down into and nearly to the bottom of the sealing tank T 'which tank has an overflow pipe t. The discharge pipe D is fitted with a suit -able valve d. A pipe 'D. fitted with a valve leads from the bottom of the cylinder A and- C is a steam pipe which opens into the cylinder below a' number of -the up er diaphragms, but above the level to WhlCh the converting column of liquor will in practice ever rise as hereinafter'described. The pipe C is fitted with a hand valve 0 and also with a pressure reducin valvec. The cylinder A is provided with safety .valve S, pressure gage G, and an air vent gipe V, with valve 12, leading into the pipe '105 beyond the valve d, and communicating with the heater H through the pipe D chamber T and-pipe h. -'Means for indicate ing the height of liquor in the cylinder are provided, such asthe gage glass R on the side of the cylinder. A small test pipe E with valve 22 leads from the discharge pipe D at a point below its valve d into the tank tom, shown in vertical axial section in the drawing, containing near the top a distributing device such as a horizontal perforated plate p upon which delivers through the top of the heater the liquor conducting pipe h which is fitted with a hand valve '0 and leads from a source of supply of the mixture of starch, water and converting agent such as muriatic acid for example, which is to be treated in the apparatus being described. F mm the bottom of the heater H a pipe 12.

leads to the suction of a hi h pressure cen trifugal pump P. Into the s1de of the heater a short distance above the bottom leads the pipe h, from the pressure'reducing tank T. From the heater just below the perforated plate ;0 leads avent pipe 0 having a valve 0. This vent pipe 0 leads to a vacuum producing apparatus, such as the common ejector condenser C 5 by which a partial vacuum may be maintained in theheat'er H. H, is a heater in'which higher pressure steam is used for heating purposes. It is a" vertical cylinder clpsed top andbottom: it is shown iii vertical section from the bottom for a short distance upward to disclose'one form of internal construction. Through the bottom of the heater opens 'a live steam pipe ,W which is fitted with a hand valve ea. In the heater a little above the bottom is a perforated horizontal plate 19' just above which there opens into the heater the pipe 71?,

.which connects to the discharge nozzle of the centrifugal pump P. From the top of the heater H, a discharge pipe b leads into the converting column cylinder A above the upper diaphragm in the same. This pipe may be fitted with a thermometer for indicating the temperature of the liquid flowingfrom the heater into the cylinder A and with a check valve 42 which opens toward the cylinder A.

' The mode of using this apparatus for the .continuous conversion of starch is as follows: Air is first driven from the system by opening thevalves d, v, and 0 respectively in the pipe D, vent .pipe 'V and vent pipe 0, the latter of the heater H, and then admitting steam into the bottom of heater H" through thelive steam pipeW by opening the valve 41), When the pipes D, o, and

0 grow hot due to escaping steam the air may be considered as expelled 'and the valves in the said pipes closed. The hand valve 0 on the live steam line C to the converting column. cylinder'A is now opened, and theautomatic pressure reducing valve 0 is set to maintain a steam pressure in the cylinder corresponding to or a little above the desired converting temperature say 280 Fahr. The safety valve S is set for a little above this pressure and the centrifugal pump P is started. The mixture of starch water and acid (mixed in proportions whichare kept preferably practically constant) is now allowed to flow into the top of the heater H through the pipe it, by opening the valve 0 at a constant rateregulated by means of said" valvewhich will pass the wished for quantity of material through the system per unit of time. The starch lquor passes from the bottom of the heater H through the pipe 71. into the centrifugal pump P, which delivers the liquor as fast as it comes through the pipe 72. into the bottom of the. heater H. The centrifugal pump is so proportioned and is maintained at such a speed as will do this and deliver the liquor under such apressure as will force it up through the heater H into" the converting column cylinder A against the pressure in the latter. As soon as the starch liquor begins to enter the bottom of heater H live steam is turned into the bottom of tlie heater through the pipe W by meansof the valve to which is regulated so that the starch liquor passes from the top of the heater H through the pipe I) and check valve 11 into cylinder A at or a little below the converting temperature say 280 Fahr.

which corresponds to about 35 pounds pressure above atmospheric. The heated acidulated starch liquor flows on to the upper perforated plate in the cylinder A at a constant speed, viz. that at which it is delivered into the heater H throughthe pipe h. The

heater H is so proportioned in size with respect to thenormal flow of starch liquor that the latter will be init only long enough to be' converted partially, leaving a good part of the converting to be done in the cylinder/A. If conditions are maintained con- 'stant as to'rate of flow of the liquor and the quantity and pressure of steam delivered .into. the heater H, the liquor will enter the cylinder A at a conversion.

,When, in putting .the apparatus into service, as is now bem described, the starch liquor enters the cyllnder'A at the top and practically uniform state of it falls through the-perforations from diaphragm-to diaphra m until it reaches the bottomof'the cylin er. In falling through the atmosphere of steam in cylinder A, it isbrought to the desired temperature by the latter if.not already brought to that temperature in the heater H. The valve in the test branch pipe E is kept open. This permits the liquor to rise in the discharge pipe D as soon as its lower end is covered with the starch liquor. The discharge valve d is kept closed, and'the level of the liquor consequently rises in the cylinder to form the converting column of liquor. It is permitted to thusrise until the liquor flow-- a when the adequate reaction was obtained.

If this be done, the liquor flowing from the pipe D will all have been in the converting column the same length of time, namely the time'which was required to fill the cylinder up tothe said level, say to the level Z, and the liquor flowing out will be all of practically the same degree of conversion, that is I assuming the rate of delivery of the starch liquor into the cylinder, and its acidity and also the temperature in the converting columri to all remain constant. This latter will be-the case so long as the liquoradded to the column from above is of a constant temperature for no heat is added to the convert-- ing column nor any taken from 1t except such as may be lost by conduction through the walls of the cylinder which may be rendered m'Z by a suitable non-conducting cov- 'Ihe er'forated diaphragms serve to evenly ering around the surface of the cylinder.

distribute the starch liquor over the surface of the converting column of liquor in the cylinder, to cause a uniform flow downward of the liquor from the top of the'column to the outlet at the bottom of the same, and to prevent the agitation of the surface of the liquor to any considerable depth by the fallingof the liquor upon the same. The perforated diaphragm that may be next above the surface of the liquor in the converting column breaks its fall, and a the diaphragm next below the surface limits the said agita-' tion to the liquor above it. The closer together the diaphragms are the more uni; form will be the movement downward of the column of liquor throughout its entire cross section, the less will be'the agitation of the liquor column at its surface and the less will be the danger of mixture of any portion of the moving converting column of; liquor with the portions which next precede or next follow it in the column, something to be avoided in the interest of uniform conversion, While the apparatus is in service the vent valve 1) is left slightly open to permitof the escape of air and incondensable' gases which might collect at the top of the converter cylinder A.v

Any heat or vapor which may escape with the incondensable gases through the valve 4) and pipe V ultimately pass with the gases into the heater H and are utilized in heating the starch solution, while the gases escape from the heater H, through the vent pipe 0 to vacuum producing apparatus as the condenser C the valve 0 in the pipe being kept open for the purpose. By means of this vaouum apparatus and the connecting pipe 0 and valve 0 a pressure below atmosphere may be maintained in the heater H which will lower the waterboiling' temperature in the heater below the gelatinizing temperature of the starch liquors, andthereby prevent the formationof. starch paste in the heater which might interfere with the proper flow of the. starch liquor through the.

pump P into the high pressure heater H.

The lower pressurein the heater H permits a lower pressure than atmospheric in the expansion chamber T, and consequently a greater disengagement of vapor from the converted starch liquor and a greater-transfer of heat thereby to the starch liquor in. I

the heater H. It is apparent that any incondensable gases which may be contained in the starch liquor'entering the bottom of the heater H, or which may be generated v while the liquor is moving throughthis heater will all pass from the top of the latter into the cylinder A, and from it throughthe vent pipe V and intermediate connections into the low pressure heater H, and thence away through the vent pipe 0 after being cooled by rising against the fallingshower of starch liquor.

J is a pipe for. delivering into the cylinvder below the lower diaphragm in the converting column a solution of the reagent (usually carbonate of soda)- used for neutralizing the acid in the converted liquor. It-

is most convenient that this solution be of constant strength and be delivered into the converter at a constant speed. The solution .thus delivered throughthe pipe J mixes with the acid liquor and passes with it up through the discharge pipe D, and into the expansion chamber T. Therate of inflow of the neutralizing solution is regulated by suitable means as by the hand valve 7' so as to" produce in the out-flowing liquor the desired conditions with respect to neutrality .The liquor in the converting column is, with .a view to quick conversion, preferably kept at a temperature considerably above 212 Fahr., say at 280 Fahr., and at the corre- 'sponding pressure of 35 pounds above atmospheric; The converted liquor on entering the expansion chamber T in which the pressure is lower, say atmospheric, flashes 1'5 but with greater ease on account of the lower and apparatus. For this reason I neutralize the acid while the liquor is still under pressure. With less efliciency perhaps with respect to making the escaping vapors neutral,

pressure, the neutralizing solution may be delivered into the discharge pipe D above the valve 03, as by the pipe J. To better insure a thorough mixing of the neutralizing solution withthe escaping liquors and vapors the pipe 1D, may be fitted inside for a portion of its length with a spiral or other deflecting or mixing device as indicated by dotted lines at z. \Vhile the apparatus is in operation the Valve 6 in the pipe E is kept slightly open so that there is alwaysa flow of liquor through the pipe E from the discharge pipe D into the chamber T. This permits sample's being taken at any time from the branch test pipe E which will exactly show, it tested, the degree of'c'onversion of the discharging liquor.

Assuming constancy {with respect to other conditions, namely acidity, rate of flow' of liquor through the converting column, and

temperature in the-latter, the degree of con-.

version in the liquor issuing from the discharge pipe D will vary with the length or depth of the converting column of liquor in the cylinder. For example, if the surface of this column is'caused to stand at the level Z and the conversion is right for the non crystallizing product sold as glucose, the conversion with the surface of the column held at some higher level Z will be proper for the solid product sold as rape sugar?" The level of the surface of the iquor column maybe raised by closing the valve d in the discharge pipe D until the level is raised to the desired height by the inflowing liquor, and then opening the valve ol to the degree which makes the outflow of liquor equal to the inflow as indicated by the level remaining constant. The level of the liquor is lowered by opening wider the valve .d' until the level falls to the point desired, and then closing the valve until the level remains, constant. It is obvious that, maintaining a constant volume or height of converting'column. of liquor in the cylinder and a given temperature, the degree of conversion may be varied by increasing or lessening the rate of How of the acidified liquor through the converting column since they respectively lessen or increase the time the acid liquor is in the converting column and subject to its temperature. y

The cylinder A and the high pressure 'heater- H may be considered together as a converting apparatus formed of two 'connected members, in the first of which H, the starch liquor is heated approximately to the converting temperature with a partial conversion of thestarch while inthe second the conversion is completed by the heat imparted to the liquor in the first wholly or in part, while the expansion chamberT, heater H, and the intermediate connections and adjuncts may be considered as means for recovering heat-from theconverted'liquor and employing it for heating the starch liquor preparatory to its passing to the converters.

I do not limit my invention to the particular construction or details of I apparatus shown in the drawings and described in this specification.

By means of the apparatus and the mode of operation herein described, a product is obtained every constituent portion of which has approximately the same degree of conversion 'nstead of being a product which is made up of portions having various degrees of conversion, the mixture of which forms the product which is obtained by the usual intermittent method of converting starch.

So far as I am aware, no product from starch conversion as an article of manufacture and commerce has ever been made the constituent parts of which have all practically the same degree of conversion.

I now claim as of my invention:

tion of connected converting vessels, a starch heating-tank, means for continuously introducing the starch from the heating tank to the first of the converting vessels, .an expansion chamber, means for continu- 1. In converting apparatus,-the combinaously introducing the converted liquor int-othe expansion chamber and for withdrawing it therefrom, anda vapor pipe leading frplrlp the expansion chamber to the heating ta 2. The combination with a closed converter, of means for continuously supplying the same with starch and forsimultaneously and'co'ntinuously withdrawing the product ,of/ the conversion from j said converter, ,means for introducing steam into the converter in quantities suificient to maintain a pressure therein above\ atmospheric pressure and means for separating the steam from the converted liquor as it is discharged Y from the converter.

v3. The combination with a converter, of means for continuously supplying the same with starch, means for simultaneously and the conversion from the converter, means for heating the starch before it is supplied to the starch heating. tank.

theconverter, and means for separating the steam from the converted liquor as it comes from the converter and for conducting such steam to the means for heating the.

starch before it is supplied to the converter.

4. The combination with a closed converter, comprising a plurality of connected vessels, of means for maintaining steam in said vessels at pressure above atmospheric pressure, means for continuously supplying said converter with. starch, and means for simultaneously and continuously withdrawing the product of such conversion from said converter and for separating the steam therefrom.

5. Converting apparatus, comprising a closed converter,- means for maintaining a pressure in said converter above atmosphericpressure and an expansion chamber which receives the product of the conversion from the converter, the ex ansion chamber.

provided with a vapor disc arge pipe and aseparate liquor discharge pipe.

6. Converting apparatus, comprising a converter, an expansion chamber which re- 'ceives the product of the conversion from the converter, a starch heating tank, means for introducing the starchfrom the same into the converterpand a vapor discharge pipe leading from the expansion chamber to 7. Converting apparatus, comprising a converter, a starch heating tank, means for conducting the starch from the heating tank to the converter, and means for-taking steam from the converter to the heating tank. I

' 8, Converting apparatus, comprising two connectedconverting vessels, means for introducing the starch into the first of said vessels, means for heating said liquor in said vessels, and means for withdrawingthe product of the conversion from the second of said vessels. I 9. Converting apparatus, comprising two connected converting'vessels, means for in: v,

troducing the starch into the first of said -vesse1s, means for heating said liquors in .sels being so constructed as to saidvessels and for agitating the liquors in the first. vessel, and means for withdrawing the productof the conversion from the second of said vessels, the second of said vesgive a rela-- tively undisturbed flow.

.10. Converting apparatuspcomprising a.

plurality of connected converting vessels, means for continuously supplying the llquor to be converted to the first of said vessels,

means for continuously withdrawing the liquor from the last of said vessels,,and an expansion tank which receives the liquor from the convertln vessels sald ex ansion tank being provided with a vapor discharge;-

and a liquor discharge.

11. Converting apparatus, comprising a plurality ofconnected converting Vessels,

means for continuously supplying the liquor 7 to be converted to the firstpf said vessels,

means for continuously withdrawing the liquor from the last of said vessels, an expansion tank which receives the, liquor-from the converting vessels, said expansion tank beingprovi'ded with a vapor discharge and l a liquor discharge, and/a starch heating tank connected with the vapor discharge of the expansion tank. I

12. Converting apparatus comprising a converting vessel in which the starch is heated" under pressure, a heating tank for heating the starch before it'goes to the converterfan expansion chamber which receives the starch from the converter, and means for conducting steam from the expansionchamher to the starch heating tank. q 13. Converting apparatus-, comprising a converter in which the starch is heated under pressure, said converter having a steam vent, a heating tank for heating the starch fhefore it goes to the converter, and a steampipe leadingfrom the steam vent of; the converter to the heating tank; r

14. In converting apparatus, the

combina- 1 tion with a closed converter, ofa feed pipeleading into saidloonverter, me'ansfor maintaining-a pressure in said converter above atmospheric pressure, a discharge pipe'extending upward from said converter and opening beneath the'surface of. the liquor therein, through. which the converted liquor is discharged, and an expansion tank into which said discharge pipe delivers,.provided with a liquord'ischarge pipe and a separate vapor discharge pipe.

15. In a starch. converting vessel containing. a flowing column of starch li nor in process of conversionas it moves a i ng in the column of liquor, means for delivering theastarch liquor to the liquor column at one end approximately evenly distributed over the cross section of thecolumn of li q-;

nor; and mean's'fo'r drawing the liquor away from the other end of the column.

. 16. In a starch converting vessel contain ing a flowing column of starch li nor in process-of conversion as it moves a ong in and means tor withdrawing the liquor from.

the other end of the liquor column with approximate equality from the entire cross section of the column.

18. A closed converting vessel adapted for converting acidified starch liquors underthe influence of pressure and heat a. and means of introducing a neutralizing agent into the converted liquor while still un er pressure.

' 19. A closed converting vessel adapted for converting acidified starch liquors under the influence of pressure and heat and means of introducing a neutralizing agent into the converted liquor while still under pressure, a

agent.

suitable heating device and means for utilizingthe heat in the neutralized converted liquor in the heating device for heating purposes. Y .o *1.

20. A closed converting vessel adapted for converting acidified starch liquors under the influence? of pressure and heat and means of introducin a neutralizin agent into the converted liquor while sti 1 under ressure, and means for disengaging vapors one the neutralized converted liquor, and thereby producing neutral vapors for heating purposes. V

21. A'closed converting vessel adapted for convertingacidified starch liquors in the presence of heat'and pressure, a discharge pipe connecting to. the converting vesselfor conducting the converted liquor from the converting vessel and means for introduc ing a neutralizin agent into said pipe simultaneously'with t e passageof the converted liquor through the same. 7 a

22. A closed convertingvessel adapted for converting acidified starch liquors in the presence oflheat and pressure, a discharge pipe connecting to the converting vessel for conducting the converted liquor from the converting vessel and means for introducing a neutralizing agent into said'pipe simuL taneously with the passage of the converted liquor through, the same, and bafiies in the discharge pipe to assist in the mixin of the discharging liquor and the neutralizing 23. A closed converting vessel adapted for converting starch liquors through the influence of heat and pressure, and means for disengaging vapors from the hot liquor con verted in said converter at pressures below atmospheric.

24(A. closed converting vessel adapted to. converting starch liquors through the influence of heat and pressure, an expansion chamber, conduits between it and the converted adapted for conveying the converted liquor from the converterinto the expansion chamber and means for maintaining a pressure below atmospheric in the expansion chamber during the passage of the converted I of starch liquor heaters connected in series by liquor conducting interconnectin pipes,

first heater of the series, a liquor conducting pipe leading from the last member of the series into the converting vessel, means for forcing the starch liquor through the heaters in succession and into the converting vessel and means for supplying steam to the several heaters respectively at difi'erent pressures increasing in the heaters with their distance from the initialheater of the series.-

ln testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses,

S. MORRIS. LILLIE.

Witnesses:

, JOHN J, WALTER,

COLIN D. SMITH,

a starch liquor supply pipe leading into the v 

